But space physicists say stronger space storms are capable of knocking out the power grids of China and the U.S.

The most recent solar explosion, caused when magnetic energy from the sun is converted into hot energetic moving gas and ejected from its surface, was classed as M-2 or ‘medium sized’. A coronal mass ejection accompanied the explosion, NASA said.

Solar flares can blast energy particles at close to the speed of light toward Earth, damaging solar cells on spacecraft and causing conductor components in communications devices to breakdown.

NASA has said the most recent solar eruption was not pointed directly at Earth, so disruptions are expected to be fairly small and any effects would be experienced over the next day or so.

Professor Iver Cairns from the University of Sydney’s School of Physics, said the sun was entering a period known as “solar maximum” – part of an 11 year cycle where it was particularly active.

There are between one and 10 major geomagnetic storms a year, he said, with most having little impact on Earth.

“However, there’s a prediction from the American National Academy of Sciences on space weather. They said if a certain geomagnetic storm that occurred in May 1921 occurred again today, the US power grid would be severely damaged,” he said. “About 30% of its transformers and therefore the entire power system would be out of action for potentially about 10 years with a price tag of greater than $US1 trillion.”

“If that happened to the Americans, it could also happen to the Chinese and the northern portions of Europe where you are close to the aurora zones. Those are our main trading partners and allies so if they have costs in the order of trillions, we would have huge problems as well.”

Professor Cairns said huge bursts of energy from the sun could damage power lines, telephone lines, mobile telephone communications and GPS.

“Since GPS is vitally important to airline transport, shipping, trucks, time stamping financial transaction on the stock exchange, you can see there would be major issues,” he said.

However, such large geomagnetic storms are rare, he said. The most recent solar flare was on a much smaller scale and most of its effects would already have been felt by now.